Incorporation of fluoroprolines to proctolin: Study on the effect of a fluorine atom toward peptidic conformation
摘要:
In spite of quite small steric perturbation, substitution of proline (Pro) in the target pentapeptide proctolin (Arg-Tyr-Leu-Pro-Thr) for (4R)- as well as (4S)-4-fluoroproline led to apparent alteration of the pyrrolidine ring structure which eventually resulted in the significant conformational change of the whole molecules which was assumed on the basis of their NOESY spectra. (C) 2008 Elsevier B.V. All rights reserved.
Synthesis of peptide chloromethyl ketones and examination of their inhibitory effects on human spleen fibrinolytic proteinase(SFP) and human leukocyte elastase(LE).
Various substrate-derived chloromethyl ketones were synthesized by a conventional method for the purpose of obtaining specific and potent irreversible inhibitors for human spleen fibrinolytic proteinase (SFP) and human leukocyte elastase (LE) in order to compare the properties of SFP with those of LE. It was found that Boc-Ala-Tyr-Leu-Val-CH2Cl among the peptide chloromethyl ketones exhibited the most effective and specific inhibition of SFP and LE. The two enzymes were inhibited by peptide chloromethyl ketones having a Val residue at the C-terminus in a similar manner, demonstrating a similarity between SFP and LE.
Synthesis and effects of two peptide fragments of thymopoietin II on E-rosette forming cells in the uremic state.
作者:TAKASHI ABIKO、MIHOKO KUMIKAWA、HIROSHI SEKINO
DOI:10.1248/cpb.27.2233
日期:——
Two peptides, H-Lys-Asp-Val-Tyr-Val-Gln-Leu-Tyr-Leu-OH and H-Arg-Lys-Asp-Val-Tyr-Val-Gln-Leu-Tyr-Leu-OH (fragment of thymopoietin II), were synthesized in a conventional manner utilizing the hydrogen flluoride procedure, and were tested to determine their effects on E-rosette forming cells in the uremic state. The synthetic decapeptide increased E-rosette forming capacity in the presence of uremic serum. The synthetic nonapeptide had no effect on the E-rosette formation inhibiting activity of uremic serum.
In spite of quite small steric perturbation, substitution of proline (Pro) in the target pentapeptide proctolin (Arg-Tyr-Leu-Pro-Thr) for (4R)- as well as (4S)-4-fluoroproline led to apparent alteration of the pyrrolidine ring structure which eventually resulted in the significant conformational change of the whole molecules which was assumed on the basis of their NOESY spectra. (C) 2008 Elsevier B.V. All rights reserved.